As a well is drilled, surveys measuring depth, inclination, and azimuth of the well are acquired. The trajectory of the well may be reconstructed based on these surveys. The set of surveys and associated uncertainties provide a “survey program.” The different surveys of a survey program may cover the same or overlapping depth intervals. Thus, one task of building the survey program may be to select a survey to use in such intervals. Generally, the uncertainty of the surveys generated by measurements taken by the individual tools is known or determined, and thus the survey measured with the lower or lowest uncertainty at a particular depth may be selected for the survey program.